This invention relates to a heat exchanger, particularly a multi-shell heat exchanger comprising at least two interconnected spherical shells wherein one shell encloses the other.
Heat exchangers are well known in the prior art and are available in varying sizes and cooling capacities. The design of heat exchangers is often dictated by the intended use of the heat exchanger. Use parameters such as volume, flow rate and temperature differential of the heat exchange media and other variables must be considered in designing a heat exchanger. It is also desirable that heat exchange between fluid media be accomplished in the shortest time possible. In this regard, it has been found that the contact surface area between heat exchange fluid media is directly related to the efficiency of the heat exchanger. Prior art devices have taken various forms to increase the contact surface area between the heat exchange fluid media. Some prior art heat exchangers include very long concentric tubes varying in length from several feet to 20 feet or more. Other prior art devices include a large outer shell with a plurality of small diameter tubes extending through the outer shell. In some prior art devices the small tubes are coiled within the outer shell to increase the surface contact area.
The heat exchanger of this disclosure utilizes a plurality of spherical shells arranged one within the other, the innermost shell being volumetrically the smallest and enclosed by successively larger shells. The spheres provide a maximum surface contact area for the heat exchange media for a given volume of structure. Thus, the heat exchanger of this disclosure provides a maximum cooling area for a given space. Space limitations are an important consideration, particularly in a laboratory where a 10 or 20 foot heat exchanger tube can not be conveniently accommodated. The apparatus of the present disclosure overcomes the problem of space limitation by utilizing a plurality of spherical shells to provide a large cooling contact area for the heat exchange media in the smallest volumetric space.
The temperature differential of the heat exchange media is an important consideration in the design of a heat exchanger. Thermodynamic stress resulting from the temperature difference between the heat exchange media increass proportionally to an increase in temperature differential. The spherical structure of the heat exchanger of this disclosure is well suited to endure thermal shocks resulting from sudden temperature and pressure differences. The spherical construction of the heat exchanger enables the heat exchanger to withsand the greatest thermodynamic stress for a given cooling area.